RV Sewage and Dumping Basics

For many, this is the single most terrifying part of learning to use a new camping trailer, but it doesn’t have to be! It’s a simple system, and a quick routine should have you worry-free in no-time.

Common Terms You’ll Hear When it Comes to RV Tanks:

Gray Water – waste water that comes from sinks and showers… not the toilet

Black Water – waste water that comes only from the toilet

Bayonet Fitting – the part your sewer hose attaches and “locks” onto 

Blade Valve – this is the type of valve that keeps your tanks closed until you’re ready to “dump” the tanks. You pull the handles on these valves to open them.

Sewer Hose – This is a hose that transports waste water and matter from your holding tanks to the sewage inlet at the campsite or at the dump station

Dedicated “Rinse” Hose – NEVER use your fresh water hose for any activities that involve your tank dumping equipment and processes.

Monitor Gauges – these are gauges found inside your trailer, usually on the “convenience” or “monitor” panel. They give you an “idea” but not the most precise level of contents your holding tanks are holding. (These gauges are part of the 12-volt system, so you’ll need your trailer’s battery or shore power.)

Best Practices When Dumping RV Tanks:

• Never allow both the gray and the black tank valves to be open at the same time. This prevents cross-contamination and odor-transfer.
• Keep some water/solution in your black tank to prevent compounding and drying of matter in this tank. You want everything to break down and flow out of the tank, easily.
• Never wash food particles, dirt, or sand into either of the holding tanks. 
• Use proper chemicals in both tanks to break down all the waste that goes down (follow the directions on the chemicals you choose to purchase)
• ALWAYS prep the toilet for use, and make sure you keep some water in the toilet bowl before using it. Keeping a few cups-worth of water in the bowl between uses not only keeps the toilet’s valve pliable, but it also keeps potential smells from coming up from the black tank into the trailer.
• Gloves if you want ‘em… but it isn’t mandatory. (DO wash your hands after working with your waste handling equipment, regardless. You’ll feel better.)

Let’s Dump!

So…you’re already connected at your full-hookup site, it’s been a few days, and the monitor shows 2/3rds or 3/4s full. What do you do?

Single Outlet RV Dump Systems

If there’s only one dump fitting/outlet… then your gray and black water tanks empty through the same port.

1. Verify that your sewer hose is properly connected at the trailer fitting and at the sewer inlet
2. Close the gray water dump valve by pushing the gray handle “in”
3. Open the black water dump valve by pulling the black handle “out”, about 6 inches. You should immediately notice that the tank is emptying through the hose and into the sewer inlet
4. IF your trailer has a “black tank flush” fitting… don’t use it at your campsite. Use the black tank flush at a separate dump station to prevent any chance of backflow contamination traveling to the campsite spigot.
5. When the black tank flow has slowed, you can flush a bit of water through the tank using the toilet. (This rinses the black tank and the hose a little before moving on.)
6. Close the black tank valve by pushing the black handle “in”
7. Open the gray tank valve and run a fair amount of water through the tank using an interior faucet to “rinse” the sewer hose.
8. Add tank treatment to the tanks according to the directions on the chemicals you have purchased.
9. Add some water to the black tank using the toilet to prepare it for use. Again… to avoid a compacted “poo pyramid,” you must keep some water and tank treatment in the black tank.

Dual Outlet RV Dump Systems

If there are two dump fittings/outlets… then your gray and black water tanks empty through separate ports.

1. Close the gray water dump valve by pushing the gray handle “in”
2. Verify that the black tank’s valve is close by pushing the black handle “in”
3. Relocate the sewer hose from the gray tank’s outlet to the black tank’s outlet
4. Verify that your sewer hose is properly connected at the trailer’s black tank fitting and at the sewer inlet
5. Open the black water dump valve by pulling the black handle “out”, about 6 inches. You should immediately notice that the tank is emptying through the hose and into the sewer inlet
6. IF your trailer has a “black tank flush” fitting… don’t use it at your campsite. Use the black tank flush at a separate dump station to prevent any chance of backflow contamination traveling to the campsite spigot.
7. When the black tank flow has slowed, you can flush a bit of water through the tank using the toilet. (This rinses the black tank and the hose a little before moving on.)
8. Close the black tank valve by pushing the black handle “in”
9. Relocate the sewer hose from the black tank’s outlet to the gray tank’s outlet
10. Partially fill the gray tank with water.
11. Open the gray tank valve and run a fair amount of water through the tank using an interior faucet to “rinse” the sewer hose.
12. Remove your gloves
13. Wash your hands… until you feel sufficiently clean…. Then wash just a bit more.
14. Add tank treatment to the tanks according to the directions on the chemicals you have purchased.
15. Add some water to the black tank using the toilet to prepare it for use. Again… to avoid a compacted “poo pyramid,” you must keep some water and tank treatment in the black tank.

Using an RV Dump Station instead of a Full-Hookup Situation

The procedures are nearly identical when you arrive at a dump station, except here you get to use your dedicated “rinse” hose to operate your black tank flush and also to manually rinse out the sewer hose before packing for travel. 

***NEVER use your fresh water hose for any activities that involve your tank dumping equipment and processes. 

****NEVER use a POTABLE WATER spigot with your rinse hose to operate your black tank flush or to rinse out your sewer hose.

Suggestion: Don’t fill up your tank’s fresh water holding tank at the “fresh” or “potable” water faucet near the dump station. People make mistakes all-to-often and use that hose and faucet for the wrong purposes. You don’t want to suffer contamination from their errors.

Using Your Black Tank Flush System

1. We don’t recommend using your black tank flush at a full-hookups site to prevent back-wash contamination to the camp site’s faucet/spigot
2. We DO like our trailers sitting close-to-level, or slightly downward toward the dump valve side of the trailer. (You want everything to travel downhill as much as possible.)
3. While you’re emptying the contents of your black tank at a separate, dedicated dump station.
4. Use a hose that’s dedicated to only sewage purposes (NEVER use your fresh water hose when working with or around your dumping system and equipment. 
5. Connect the dedicated rinse hose to the trailer’s black tank flush fitting.
6. Connect the free end of the rinse hose to the non-potable water faucet/spigot at the dump stations. ***NEVER use the fresh or potable water faucet/spigot to connect your rinse hose or to wash out your sewage equipment.
7. VERIFY that the dump valve for the black tank is STILL OPEN
8. Turn on the water full blast for 5 to 10 minutes to allow the jets in the black tank to rinse the interior of the black tank.
9. Turn off the water and disconnect the rinse hose from the trailer.
10. Continue with your usual dumping procedure.
11. Here, you should use the rinse hose to rinse out your sewer hose before removing it from the sewer inlet.
12. Throw away your gloves
13. Wash your hands… twice